The moon phase

How Does A Moon Phase Watch Work

It seems that we’re always keen to understand the movement of the sun, the moon and the constellations.

Back in the days, horologists made progress from the sundial to gear and hand, which included tracking the lunar cycle. Even though the sun’s arc is essential on days and seasons, the moon told us about the passing of months.

We count 29 and half days from new moon to full moon, which gives us a regular cycle, a life cycle for so many centuries.

The moon phase

A moon phase watch tells you in fact about the current phase of the moon, just the way you see it in the sky. A watch like this show you in an opening of the dial how the moon passes across the sky. It’s one of the most fundamental watches due to its graphical representation of the time passing. This is why it’s so different from the watches that feature accurate and yet, dull hands and numbers of other watches.

The “moon phase” is the lighted area of the moon that we may see as it travels all around the Earth. The movement of the Earth and the moon’s position tells us that we always seeing them from a different view. Astronomers do use all sorts of names for moon’s phases, but there are only 4 of them that count for most of us.

When the moon and sun are aligned on the same side of the Earth so we practically don’t see a moon at all, we talk about the “new moon”. The “first quarter” happens when the right-hand side of the moon is in the sun’s light.

As the entire surface is lit up, we get to notice the “full moon”, whereas the “last quarter” happens when the left-hand side is easy to see by us.

All of these phases take around 29 and half days, which is the average length of a calendar month. It sorts of makes sense that the modern calendar is related to the phases of the moon. It was the Roman political and religious fuss that added/subtracted days to some months, which is why not all months are 29 and a half days.

Why is it important for time telling?

The moon has always been important for a man’s existence so keeping its track became essential for all. At some point, the moon phases appeared in the sophisticated pocket watches late in the 19th and early 20th century. In addition, when the pocket watch turned into the wristwatch, the moon phase migrated to the wrist as well.

The moon phase shows us in fact the link between the watchmaker and the time itself.

The mechanism behind

A typical moon phase watch has behind its dial a disc with two identical moons on it. The disc rotates a whole cycle for 29 and a half days, with the waxing and waning face of the moon explained by the curved edges of the dial opening. A 59-tooth gear drives the moon disc, whereas it’s moved forward by a mechanical finger every 24 hours. This gives us one complete rotation for the entire lunar cycle. Well, almost, anyways.

The reality

As the real lunar cycle is in fact 29 days, 12 hours and 44 minutes (29.53 days for more precision J), the moon isn’t that helpful after all. Sure, this accuracy works for many of us, but a watchmaker needs a lot more than that and don’t just settle for anything less.

When you’re off by .03 days per month, it means the whole moon phase cycle is off by one full day every two years, seven and a half months.

In order to surpass this difference between the measured lunar cycle and the moon phases per say, us needed a more complicated mechanism. This mechanism features a 135-tooth gear that drives the moon disc. This little detail increases the precision of the movement so that the moon phase’s intricacy is of by only a day once every 122 years. Therefore, it’s not up to you, by to your grandson to make some small adjustments, way ahead into the feature.

Our life doesn’t depend that much on the moon’s orbit anymore and the wristwatch isn’t just what it used to be anyways. Within all of these various smartwatches, smartphones, the moon phase watches have their charm, reminding us how little we are in this Universe.

It all depends on you which way you want to go when getting a watch. If you want it to keep you connected at all time with all of your friends, don’t hesitate to get a smartwatch. If you’re only for the time telling, stay true to your beliefs and get a moon phase watch. After all, time flies just the same!